Micrometric control for boom hoisting means



y 1952 F. L. WHITE 2,602,551

MICROMETRIC CONTROL FOR BOOM HOISTING MEANS Filed April 21, 1949 3Sheets-Sheet 1 FIG. 5.

13 13 Z/ 1' w b l 29 INVENTOR. FRED l WHITE FIG. I. Z9 24-" BY ATTORNEYF. L. WH |T MICROMETRIC CONTROL FOR BOOM HOISTING MEANS Filed April 21,1949 3 Sheets-sh 2 &

nmmmuuum mvamoa; FRED L. WHITE RNEY.

y 1952 F. WHITE MICROMETRIC CONTROL FOR BOOM HOISTING MEANS 3Sheets-Sheet 3 Filed April 21. 1949 HV/R v lli FIG. 4.

INVENTORZ FRED L WHITE ATTORNEY.

Patented July 8, 1 952 Mro'aoME'rRIo ooN'rRoL FOR/BOOM.

HOISTING MEANS Fred L. White, Marion, Ohio, assignor to The OsgoodCompany, Marion, Ohio, a corporation of Ohio Application April 21, 1949,Serial No. 88,746

8Claims. (c1. sin-59) V This invention relates to portableself-propelled hoisting equipment and is more particularly directed to ahoisting means for the boom whereby the unpivoted end of the boom may beaccurately and minutely moved from one vertical position to another. J pV The object of this invention is to provide a hoisting means for thelongitudinally extended boom on a hoisting device so that its unpivotedend can be moved between two given radial positions and in small degreesof movement with a very high degree of precision and accuracy.

Another object of the invention is to provide a means for controllingthe radially outward position of the unpivoted end of a longitudinallyextended boom which comprises a cable reeving means and a pressure fluidmotor unitand in which the former controls'the booms major verticalmovements for its unpivoted end and in which the pressure fluid motorunit controls the booms smaller vertical movements for its unpivotedend. f

Another object of the invention is to provide a means for moving theunpivoted end of a boom for ahoisting machine in which a cable reevingmeanslcontr'ols the larger movements thereof and in which the smallerprecision movements of the unpivoted end are controlled by a pressurefluid operated means that operates in connection with the cable reevingmeans.

The invention primarily consists of a boom that is pivoted to a suitablesupporting member and means on the latter for supporting the hoistingmeans for the unpivoted end of the boom. This hoisting means includes acable reeving device by means of which the unpivoted end of the boom ismoved through the larger ranges of movement. Pressure fluid operatedmeans controlled by a three way throttle valve is associated with thecablereeving means for moving the unpivoted end of theboom through thesmall, accurate and precise ranges of movement whereby loads suspendedfrom a load supporting hook and its cable can be accurately andprecisely located with no danger of having the load slip positionanclall under the complete control of the operator.

In the drawings: I

Fig. 1 is a side elevational view of a hoist incorporating theinvention;

Fig. 2 is an enlarged side elevational view of the gantry and the partssupported thereby;

Fig. 3 is a front elevational view of the gantry illustrated in Fig. 2with parts omitted to show detail;' 3 g Fig. 41s a rear elevational viewof the gantry illustrated in Fig. 2 with parts omitted to show detail;and 1 Fig. 5 is a view of a part of the cable and sheaves shown inFig. 1looking in the direction (if the line 55. p I I The invention'isincorporated in a hoisting mechanism illustrated in the several views ofthe drawing in which I is an upper body of a portable self-propelledhoist that is rotatably mounted on a suitable chassis 2 which includesendless track type traction members and a suitable prime mover andcontrols therefor may be provided (not shown) in the upper body asiscustomary in the art. v V

A. boom 3 is pivotally supported on theupper body I in a conventionalmanner. This boom has a length much greater than those on ordinaryhoists and frequently has a length of ninety feet or more. This is thetype of mechanism used on hoists employed in construction work forraising beams or other structural members and then accurately locatingthem in'the desired position. A hoisting means, shown in dotted lines,is mounted on the upper body from which a cable 3 extends to the upperend of the boom where it is threaded over a suitable sheave (not shown)and a grab hook is usually provided on the end of the cable to whichloads may be secured all of which is arranged as is well understood inthe art.

A gantry is'mounted on the upper body which is made to extend anappreciable distance above the cab comprising a part of said upper body.The gantry comprises a pair of uprights 4, normally supporting some ofthe hoist operating mechanism, secured to'frame 5 constituting theplatform or deck for the upper body I. A pair of gantry legs 6, 6 isconnected'to brackets 6' with one of the legs being secured to eachbracket. The upper end of the gantry legs 6 are secured to a bar '1 withthe legs positioned at the opposite ends of said bar; A pair of backlegs '8, 8 made up of two angularly related parts extend betweefi the Ibar 1 and the frame 5, the lower end of the back legs 8 being secured tothe frame 5 by pins l0 suitably disposed in brackets provided on saidframe. A bar 9 isconnected between the upper end of the uprights 4 andit also extends through enlargements on the back legs 8. The gantry; istherefore a rigid sturdy structure for supporting the unpivoted end ofthe boom 3.

Hoisting means for the unpivoted end/of the boom are connected betweensaid end of the boom 3 and the upper end of the gantry, one part ofwhich comprises a pair of pressure fluid operated motors ll, Hone end ofeach motor being pivled to a sheave l8 rotatably mounted on a jack shaft20, then is led downwardly and passed around sheaves I3, then upwardlyand around sheave l9 rotatably supported on the jack shaft and is thenled down to the shackle bar [2 where it is secured to an anchor 21connected thereto. A cable 22 is connected between the ends of jackshaft 20 and the unpivoted end of the boom 3. The latter cable completesthe connecting link between the unpivoted end of the boom and thegantry. The unpivoted end of the boom is raised and lowered by reevingand unreeving the cable M on the drum l5 and by the operation of thefluid motors ll.

The fluid motors II are operated by pressure fluid derived from a pump23 which draws fluid from a tank 24. Conduit 25 conducts pressure fluidto three way valve 2 6 acting as a reversing and throttle valve, andfrom said valve fluid is conducted to one end of each of the motors l lby conduit 21. Fluid is conducted to and from the other end of themotors II by conduit 28 which also connects to the valve 25 and conduit29 is a return passageway connected between the valve and the tank 24.Valve 26 is adjusted by handle 30 so that fluid can be directed toeither end of the motors l I. I

the drum l5 and because cable [4 will not reeve uniformly thereon theboom may drop a considerable distance because of cable slippage whilebeing wound and unwound. The fluid motors are actuated for accomplishingsmall adjustments in elevation of the boom which can be accuratelycontrolled by the three way or reversing valve 26.

Assume that a boom ninety feet in length is connected to the frame 5 ofthe portable hoist. With the cable organization disclosed which iscustomary in the art it will be necessary to reeve and unreeve' from thedrum !5 twelve feet of cable to change theoperating radius of the boomfrom twenty to forty feet. When the boom radius moves between the samedistances by means of the fluid motors they need only move four feet,

therefore a comparatively short motor action will move the boom the samedistance in a much shorterspace of time and requiring shorter traveldistance of the actuating means. The latter mo -.tion or that of" themotors H, H is performed rapidly and accurately and can be done in verysmall precise amounts, tantamount to micro- -metric accuracy. When thefluid motors are hook hoist. 'The cable tends to pile up on therelatively narrow drum and frequently slips when piled thus permittingthe unpivoted end of the boom to drop as much as several inches therebyendangering personnel and any load that may be carried by the grab hook.The instant invention obviates these disadvantages and in additionprovides the very reliable and desirable result that a load may bepositioned with extreme accuracy. Also, the unpivoted end of the .boom

-may be selectively controlled by a simple extensible fluid motor andassuming that it has a ,four foot stroke its motion may change theeffective boom operating radius twenty feet, rapidly and safely, and maybe changed slop/1y with extreme precision. Changes in boom length willproduce proportionate changes in movements and by changing the operatingranges of the fluid motors corresponding changes in effective boomradius can be made.

The foregoing mechanism provides an effective means for making majorchanges in boom elevation with the cable reeving mechanism andmicrometric changes in boom elevation, and therefore grab hookelevations, with the fluid motor portion of the boom hoisting mechanism.

That which is regarded new, novel and useful and which is sought to beprotected by Letters Patent of the United States is as follows:

1. A hoist comprising a frame; a boom, one end of which is pivoted tosaid frame, its other end being unpivoted; a gantry on said frame; meansextending between said gantry and the unpivoted end of said boomincluding aserially connected cable and a piston-cylinder type ofpressure fluid operated means; means for reeving said cable for movingthe unpivoted end through large vertical adjustments; and means foractuating said pressure fluid operated means for moving the unpivotedend vof said boom through minor vertical adjustments.

2. A hoist comprising a frame; a boom; means for pivoting one end ofsaid boom to said frame, the other end of said boom being unpivoted; agantry on said frame; piston-cylinder type pressure fluid means.connected to said gantry; cable means connected in series with saidpressure fluid operated means, the cable being operative on theunpivoted end of said boom, said cable including a portion divided intoa number of strands; means for winding and unwinding said portion ofsaid cable for moving the unpivoted end of said boom for making largevertical adjustments thereof; and means for operating said pressurefluid means for moving the unpivoted end of said boom for making smallvertical adjustments thereof.

'in end to'end relation with said cable means;

means for reeling and unreeling said cable means for moving theunpivoted end of the boom large distances; and means for operating saidpressure fluid operated means for moving the unpivoted end of said boomsmall distances.

4. A hoist comprising acable means connectable to the unpivoted end of aboom; a shackle bar; means for associating said cable means with saidbar; extensible pressure fluid operated means connectable to saidshackle bar and serially connected to said cable means; meansjforactuating a portion of said cable means for imposing large movements onsaid boomend; and means for actuating said pressure fluid means forimposing small movements on said boom end. 1f.

5. A hoist comprising a frame; a boom; means for pivoting one end ofsaid boom to said frame, the other end of said boom being unpivoted; agantry mounted on said frame; a pair of extensible pressure fluid'motorsconnected to said gantry; a shackle bar connected to said pressure Ifluid motors; a jack shaft; a cable connected between the unpivoted endof said boom and said jack shaft and connected in series with saidpressure fluid motors; cable means connected between said jack shaft andsaid shackle bar and serially connected with said pressure fluid motors;means for actuating said last mentioned cable means for moving theunpivoted end of said boom through large degrees of adjustment; andmeans for actuating said pressure fluid motors for moving the unpivotedend of said boom through small adjustments.

6. A hoist comprising a frame; a boom; means for pivoting one end ofsaid boom to said frame,

the other end of said boom being unpivoted; a

gantry mounted on said frame; pressure fluid mo-v between the unpivotedend of said boom and said gantryincluding multiple strand cable meansand an extensible pressure fluid operated means in serial relation; andmeans for actuating said pressure fluid means for moving the unpivotedend of said boom limited distances.

8, A hoist comprising a frame; a boom; means for pivoting one end ofsaid boom to said frame,

' the other end of said boom being unpivoted; a

tor means connected to said gantry; cable means including a multiplestrand cable means connected between said pressure fluid motor means andthe unpivoted end of said boom in serial relation therewith; means foractuating said multiple strand cable means for making large verticaladjustments of the unpivoted end of the boom; and means for operatingsaid pressure fluid motor means for making small vertical adjustments ofthe unpivoted end of the boom.

7. A hoist comprising a frame; a boom; means for pivoting one end ofsaid boom to said frame; a gantry on said frame; and means connectedgantry on said frame; means connected between said gantry and theunpivoted end of said boom which includes cable means and an extensiblepressure fluid motor means in serial relation therewith; means foroperating said cable means for moving the unpivoted end of said boomlarge distances; and means for actuating and controlling said pressurefluid motor means for moving the unpivoted end of said boom smalldistances. FRED'L. WHITE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 710,472 Lake Oct. 7, 1902 860,761McCullough July 23, 1907 1,198,833 Galvin Sept. 19,1916

2,139,960 Kauffman Dec. 13, 1938 2,168,128 Kervarrec Aug. 1, 19392,433,598 Chadwick Dec. 30, 1947 2,475,963 Howell July 12,1949

Huston Aug. 23,

